This application claims the benefit of Korean Application No. 2002-59371, filed Sep. 30, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a maintenance apparatus of an inkjet printer, and more particularly, to a maintenance apparatus of an inkjet printer and a wiper-positioning method to precisely control a wiper stop position to prevent damage to the printer due to friction contact between a carrier conveying a print head or an ink spray nozzle of a print head, and a wiper wiping the print head.
2. Description of the Related Art
Generally, an inkjet printer includes a paper feed apparatus to supply one sheet of paper at a time, a paper convey apparatus to convey the supplied sheet of paper to be printed on one line at a time, a print apparatus to print an image by spraying ink onto the sheet of paper, a paper discharge apparatus to discharge the printed sheet to an outside, and a maintenance apparatus to clean the surface of a print head nozzle of the print apparatus, collect and store waste ink, and seal the surface of the print head nozzle at the same time.
The maintenance apparatus maintains the surface of the ink spray nozzle of the print head in good condition and is thus essential to the inkjet printer of the print head to perform a satisfactory printing function.
In FIGS. 1 and 2A-2C, a general maintenance apparatus 1 used in an inkjet printer is illustrated. The maintenance apparatus 1 shown in FIGS. 1 and 2 includes a housing 5 connected with a main frame (not shown) of the inkjet printer, and a capping member 10 disposed inside the housing 5 and including two caps 16 (only one is shown) to seal the surfaces of ink spray nozzles 3 of mono and color print heads 2 (only one is shown) mounted in a carrier 6. The maintenance apparatus 1 includes a wiping member 20 disposed inside the housing 5 and including two wipers 24 (only one is shown) to wipe the surfaces of the ink spray nozzles 3 of the print heads 2, a power transmission device 30 to receive a rotation force from a bi-directional motor provided separately from a print head motor (not shown) to drive the carrier 6 with the print heads 2 disposed therein, and a capping member convey device 14, 40 to convert a rotation force of the power transmission device 30 into a vertical force and to transmit the converted force to a capping member 10. The maintenance apparatus 1 further includes a wiping member convey device 26, 28, 50 to convert a rotation force of the power transmission device 30 into a horizontal force and transmit the converted force to the wiping member 20.
The capping member 10 includes a rotation convey body 12 with the caps 16 formed on the upper surface thereof, and the wiping member 20 includes a horizontal convey body 22 with one of the wipers 24 disposed at one side.
The power transmission device 30 includes a first pulley 35 coaxially formed on a motor 32 to transmit a rotation force from the motor 32, a second pulley 37 engaged with the first pulley 35 by a belt 36, and a first gear (not shown) coaxially formed with the second pulley 37.
The capping member convey device 14, 40 includes a first connection pin 14 to hinge one end of the rotation convey body 12 to pivotably support the rotation convey body 12 in the direction illustrated by arrow A, and a first crank device 40.
The first crank device 40 includes a crank gear 39 connected with the first gear of the power transmission device 30, a crank shaft 41 coaxially connected with the crank gear 39, two first crank arms 42, 42xe2x80x2 each with one end connected on the crank shaft 41, and two first connecting rods 44, 44xe2x80x2 each with one end respectively connected with the other ends of the first crank arms 42, 42xe2x80x2 by a second connection pin 43, and other ends connected with the lower part of the other ends of the rotation convey body 12 by a third connection pin 45.
The wiping member convey device 26, 28, 50 includes two elongated guide grooves 28 formed in a length direction inside both sides of the upper portion of the housing 5, two elongated slide protrusions 26 formed on both sides of the horizontal convey body 22 to correspond with the guide grooves 28 to slide along the guide grooves 28 in a horizontal direction, i.e., the direction illustrated by arrow B, which is perpendicular to the moving direction of the print heads 2, and a second crank device 50 connected with the first gear of the power transmission device 30.
The second crank device 50 includes a crank gear 39 connected with the first gear of the power transmission device 30, a crank shaft 41 coaxially connected with the crank gear 39, two second crank arms 52, 52xe2x80x2 each with one end respectively connected on the crank shaft 41, and two second connecting rods 54, 54xe2x80x2 each with one end respectively connected with the other ends of the second crank arms 52, 52xe2x80x2 by fourth connection pins 53, 53xe2x80x2 and the other ends connected with one end of the horizontal convey body 22 by fifth connection pins 55, 55xe2x80x2.
The operation of the maintenance apparatus 1 for an inkjet printer structured as above will be described below with reference to FIGS. 1 and 2.
When the print heads 2 mounted in the carrier 6 complete printing by spraying ink on a sheet of paper while being moved left and right by a print head drive motor within a printing area, the print heads 2 move into a maintenance area, as shown in FIG. 2A.
After the print heads 2 reach the maintenance area, the bi-directional motor 32 rotates in a first direction, for example, counter clockwise, the rotation force of the motor 32 is transferred from the first pulley 35 to the second pulley 37 by the belt 36, and then finally to the crank gear 39 through the first gear coaxially formed with the second pulley 37 rotating the crank gear clockwise.
As shown in FIG. 2B, as the crank gear 39 rotates clockwise, the crack shaft 41 coaxially connected with the crank gear 39 also rotates clockwise, and accordingly the rotation convey body 12 of the capping member 10 placed in a standby position rotates counter clockwise around the first connection pin 14 by the first crank device 40 of the capping member convey device 14.
The horizontal convey body 22 of the wiping member 20 moves to the right in the horizontal direction as the slide protrusion 26 slides along the guide groove 28 by the second crank device 50 of the wiping member convey device.
As the horizontal convey body 22 moves to the right, the wipers 24 formed to protrude upward at one side of the horizontal convey body 22 also move to the right, and accordingly the wiper 24 performs a wiping operation cleaning remaining ink, fine dust, etc. on the surface of the ink spray nozzles 3 of the print heads 2.
After the wiping operation is completed, the wipers 24 are cleaned by a wiper cleaner (not shown) horizontally disposed in the housing 5, and the waste ink which was on the upper end of the wipers 24 is collected in an ink storing receptacle (not shown) disposed in the housing 5 below the wiper cleaner.
When the rotation convey body 12 continues to rotate counter clockwise by the crank gear 39, the caps 16 disposed on the upper surface of the rotation convey body 12 of the capping member 10 have one side close to the first connection pin 14, brought in contact with the surface of the ink spray nozzles 3 of the print heads 2 forming a predetermined initial contact angle and then gradually sealing the surfaces of the ink spray nozzles 3 of the print heads 2.
After the caps 16 close the surfaces of the ink spray nozzles 3 of the print heads 2, the slide protrusion 26 of the horizontal convey body 22 is blocked by a stopper 29 thereby cutting the power of the motor 32, and accordingly the first and second crank devices 40, 50 connected to the horizontal convey body 22 are consecutively stopped.
Consequently, the rotation convey body 12 of the capping member 10 is maintained to have the caps 16 in a capping position covering the surface of the ink spray nozzles 3 of the print heads 2 and the horizontal convey body 22 of the wiping member 20 in a standby position, as shown in FIG. 2C.
When a print command is received at this point, the rotation convey body 12 of the capping member 10 and the horizontal convey body 22 of the wiping member 20 perform uncapping and wiping processes in the reverse order to the above described operation by the first and second crank devices 40, 50 from the position shown in FIG. 2C.
After the rotation convey body 12 and the horizontal convey body 22 perform the uncapping and wiping processes, when the second crank arms 52, 52xe2x80x2 of the second crank device 50 continuously rotate counter clockwise, thereby coming in contact with a stopper 60, the bi-directional motor 32 rotates in the opposite direction, i.e., counter clockwise, for a predetermined duration in order to position the horizontal convey body 22, and then stops. Accordingly, the crank gear 39 of the second crank device 50 rotates clockwise by a predetermined angle until a waste ink receiving portion 25 of the horizontal convey body 22 moves to the right to be placed at a spitting position (FIG. 2A) below the ink spray nozzles 3 of the print heads 2, and then stops.
In this state, a spitting operation is performed to discharge the other color ink, air bubbles, and fine dust attached on the surface of the ink spray nozzles 3 during the wiping operation of the wiper 24.
The waste ink collected from the ink spray nozzles 3 is absorbed and stored in an absorbing body mounted in a waste ink receiving groove in the waste ink receiving portion 25. After that, the print heads 2 are moved into the printing area by the print head drive motor and perform a printing operation while moving left and right.
However, in the conventional maintenance apparatus 1 operating in such a way, the second crank arms 52, 52xe2x80x2 of the second crank device 50 are controlled to change the rotation direction by the bi-directional motor 32 after coming in contact with the stopper 60 when the horizontal convey body 22 of the wiping member 20 is moved to the spitting position.
Therefore, when the second crank arms 52, 52xe2x80x2 come in contact with the stopper 60, if the second crank arms 52, 52xe2x80x2 spring out due to the repulsive force against the stopper 60, the horizontal convey body 22 is pushed to the right as much as the second crank arms 52, 52xe2x80x2 spring out. Accordingly, when the second crank arms 52, 52xe2x80x2 change the rotation direction and rotate by a predetermined angle, the horizontal convey body 22 moves further as much as the second crank arms 52, 52xe2x80x2 spring out and stop, thereby causing a positioning error.
If the horizontal convey body 22 is erroneously positioned, the stopping position of the wiper 24 disposed on the upper surface of one side of the horizontal convey body 22 becomes inaccurate, and therefore when the carrier 6 having the ink spray nozzles 3, or the print heads 2 disposed therein, move into the printing area or return back to the maintenance area, the wipers 24 and the ink spray nozzles 3 of the print heads 2 or the carrier 6 may have friction contact, and thereby be damaged.
Accordingly, it is an aspect of the present invention to solve at least the above problems and/or disadvantages of the related art and to provide at least the advantages described hereinafter.
It is another aspect of the present invention to solve the foregoing and/or other problems by providing a maintenance apparatus of an inkjet printer and a wiper-positioning method of precisely controlling a wiper stop position to prevent damage due to friction contact between a carrier conveying a print head or an ink spray nozzle of the print head and a wiper wiping the print head.
Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The foregoing and/or other aspects and advantages are realized by providing a maintenance apparatus of an inkjet printer including a housing disposed in a maintenance area; a print head having an ink spray nozzle; a wiping member disposed in the housing and including a wiper to wipe a surface of the ink spray nozzle when the print head is in the maintenance area; a drive motor to generate a rotational force; a power transmission device to transmit the rotational force; a wiping member convey unit to receive the transmitted rotational force and to the received rotational force into a horizontal force and to transmit the converted force to convert the wiping member; a stopper to stop the wiping member convey unit to place the wiping member at a predetermined position; and a control unit to control the drive motor so that the wiping member convey unit is in contact with the stopper two times to prevent the wiping member and the wiper from being erroneously positioned due to an abnormal repulsive force occurring in the wiping member convey unit when the wiping member convey unit comes in contact with the stopper, the repulsive force being caused by an outer impact or a change in a load of the drive motor.
The control unit may include a load sensor to detect a load of the motor in order to detect when the wiping member convey device comes in contact with the stopper.
The wiping member convey device may include a guide groove formed in a length direction on an inner surface of the housing; first and second elongated slide protrusions formed on first and second sides of the wiping member to correspond with the guide groove to slidably move along the guide groove in a direction which is perpendicular to a moving direction of the print head; and a crank device connected to the power transmission device.
The stopper may include a rib disposed in the housing on a convey path of the crank arm to stop the crank arm.
According to another embodiment of the present invention, a wiper-positioning method of a maintenance apparatus in an inkjet printer includes a crank gear connected to the power transmission device; a crank shaft coaxially connected with the crank gear; a crank arm having a first end connected with the crank shaft; first and second connection pins; a connecting rod with a first end connected with a second end of the crank arm by the first connection pin and a second end connected with the wiping member by the second connection pin.
The wiper-positioning method may further include driving the wiping member convey device to move in a direction opposite to a direction in which the wiping member convey device moves to be in contact with the stopper in order to place the wiping member convey device at a stop position after the wiping member convey device is again in contact with the stopper.
In the re-contacting, the motor is driven with less speed and drive force than when the wiping member convey device is brought in contact with the stopper during the first contacting.
Additionally, timing to perform the re-contacting and the positioning are controlled by a signal from a load sensor to detect a load of the motor occurring when the wiping member convey device is in contact with the stopper.